Mobile terminal device and associated method for obtaining uplink resources

ABSTRACT

A method of allocating radio resources for uplink transmissions in a wireless telecommunications system, the method including: a first terminal device communicating a request for an allocation of radio resources to a base station; the base station determining there is an association between the first terminal device and a second terminal device based on their having similar predicted traffic profiles for uplink data; and the base station establishing a radio resource allocation for the second terminal device based on the resources requested by the first terminal device, and consequently transmitting radio resource allocation messages to allocate radio resources to the first and the second terminal devices for respective uplink transmissions based on the request for an allocation of radio resources received from the first terminal device.

BACKGROUND OF THE INVENTION

The present invention relates to methods, systems and apparatus for usein wireless (mobile) telecommunications systems. In particular,embodiments of the invention relate to communicating uplink allocationsof radio resources from a base station to a terminal device in suchsystems.

Third and fourth generation mobile telecommunication systems, such asthose based on the 3GPP defined UMTS and Long Term Evolution (LTE)architectures, are able to support more sophisticated services thansimple voice and messaging services offered by previous generations ofmobile telecommunication systems.

For example, with the improved radio interface and enhanced data ratesprovided by LTE systems, a user is able to enjoy high data rateapplications such as mobile video streaming and mobile videoconferencing that would previously only have been available via a fixedline data connection. The demand to deploy third and fourth generationnetworks is therefore strong and the coverage area needed of thesenetworks, i.e. geographic locations where access to the networks isdesired, is expected to increase rapidly.

The anticipated widespread deployment of third and fourth generationnetworks has led to the parallel development of devices and applicationswhich, rather than taking advantage of the high data rates available,instead take advantage of the robust radio interface and increasingubiquity of the coverage area. Examples include so-called machine typecommunication (MTC) applications, which are typified by semi-autonomousor autonomous wireless communication devices (i.e. MTC devices)communicating small amounts of data on a relatively infrequent basis.Examples include so-called smart meters which, for example, are locatedin a customer's house and periodically transmit information back to acentral MTC server relating to the customer's consumption of a utilitysuch as gas, water, electricity and so on. Further information oncharacteristics of MTC-type devices can be found, for example, in thecorresponding standards, such as ETSI TS 122 368 V10.530 (2011July)/3GPP TS 22.368 version 10.5.0 Release 10) [1]. Some typicalcharacteristics of MTC type terminal devices/MTC type data mightinclude, for example, characteristics such as low mobility, high delaytolerance, small data transmissions, a level of predictability fortraffic usage and timing (i.e. traffic profile), relatively infrequenttransmissions and group-based features, policing and addressing.

As a result of the increasing use of wireless telecommunicationsnetworks generally, and also the development of devices such as MTCdevices with their potential for introducing large numbers of terminaldevices into networks, there is a desire to provide for wirelesstelecommunications networks that can reliably support access byincreasing numbers of devices. This desire to support more devices,however, gives rise to an increased potential for issues with networkcongestion and interference, particular in respect of the radio accessinterface. These issues may be particularly relevant in respect of thosecommunications which are not centrally managed by a scheduler in acommunication cell of a network, such as random access communicationsfrom terminal devices seeking to access the network before having beenallocated dedicated radio resources for doing so.

There is therefore a desire to provide for telecommunications apparatusand methods which can help reduce the potential for radio networkcongestion and interference in circumstances where there might berelatively large numbers of terminal devices seeking access to thenetwork.

SUMMARY OF THE INVENTION

According to a first aspect of the invention there is provided a methodof operating a base station for allocating radio resources for uplinktransmissions in a wireless telecommunications system, the methodcomprising: receiving a request for an allocation of radio resourcesfrom a first terminal device; determining an association between thefirst terminal device and a second terminal device; and transmitting aradio resource allocation message to allocate radio resources to thesecond terminal device for an uplink transmission in response toreceiving the request for an allocation of radio resources from thefirst terminal device.

In accordance with some embodiments the request for an allocation ofradio resources from the first terminal device is received on a randomaccess channel of the wireless telecommunications system.

In accordance with some embodiments the request for an allocation ofradio resources from the first terminal device is associated with arandom access procedure of the wireless telecommunications system.

In accordance with some embodiments the radio resources allocated to thesecond terminal device correspond with an allocation of radio resourcesrequested by the first terminal device.

In accordance with some embodiments the association between the firstterminal device and the second terminal device is established based onthe first terminal device and the second terminal device having a commoncharacteristic relating to their uplink transmissions.

In accordance with some embodiments the association between the firstterminal device and the second terminal device is established based onthe first terminal device and the second terminal device beingassociated with a same terminal device classifier.

In accordance with some embodiments the terminal device classifier is aquality class indicator of respective bearers associated with therespective terminal devices.

In accordance with some embodiments the method further comprisestransmitting an access request denial message to the second terminaldevice to instruct the second terminal device not to make its ownrequest for an allocation of radio resources.

In accordance with some embodiments the method further comprisestransmitting a cease access request denial message to the secondterminal device after having transmitted the access request denialmessage to instruct the second terminal device that it is now allowed tomake its own request for an allocation of radio resources.

In accordance with some embodiments the method further comprisestransmitting an access request allow message to the first terminaldevice to instruct the first terminal device that it is allowed to makethe request for the allocation of radio resources.

In accordance with some embodiments the method further comprisesselecting the first terminal device from a plurality of terminal devicesas the terminal device to which the access request allow message istransmitted based on a transmission characteristic associated withrespective ones of the plurality of terminal devices.

In accordance with some embodiments the transmission characteristic isselected from the group comprising: a timing advance; a reference signalreceived power, a reference signal received quality, a soundingreference signal measurement at the base station, and a radio channelquality indicator.

In accordance with some embodiments the method further comprisesdetermining an association between the first terminal device and afurther terminal device; and transmitting a radio resource allocationmessage to the further terminal device to allocate radio resources foran uplink transmission from the further terminal device based on therequest for an allocation of radio resources from the first terminaldevice.

In accordance with some embodiments the method further comprisesdetermining an association between the first terminal device and aplurality of other terminal devices, transmitting an access requestdenial message to a subset of the plurality of other terminal devices toinstruct the subset of the plurality of other terminal devices not tomake their own requests for an allocation of radio resources, andtransmitting radio resource allocation messages to the plurality ofother terminal devices to allocate radio resources for respective uplinktransmissions from respective ones of the plurality of other terminaldevices based on the request for an allocation of radio resources fromthe first terminal device.

In accordance with some embodiments the method further comprisesreceiving a transmission from the second terminal device using the radioresources allocated to the second terminal device.

In accordance with some embodiments the transmission received from thesecond terminal device comprises an indication that the second terminaldevice does not require some or any of the allocated resources foruplink transmission.

In accordance with some embodiments the transmission received from thesecond terminal device comprises an indication of a request for afurther allocation of radio resources for a further uplink transmissionfrom the second terminal device.

In accordance with some embodiments the request for an allocation ofradio resources received from the first terminal device comprises arequest for an allocation of radio resources to allow the first terminaldevice to transmit a buffer status report to the base station.

In accordance with some embodiments the first and second terminaldevices are machine type communication, MTC, terminal devices.

In accordance with some embodiments the wireless telecommunicationssystem is associated with a radio interface spanning a system frequencybandwidth for supporting radio communications with a first type ofterminal device and comprising a restricted frequency bandwidth forsupporting radio communications with a second type of terminal device,wherein the restricted frequency bandwidth is narrower than and withinthe system frequency bandwidth, and wherein the first and secondterminal devices are terminal devices of the second type.

In accordance with a second aspect of the invention there is provided abase station configured to allocate radio resources for uplinktransmissions in a wireless telecommunications system, the base stationcomprising: transceiver configured to receive a request for anallocation of radio resources from a first terminal device; and acontroller unit configured to determine an association between the firstterminal device and a second terminal device and to control thetransceiver to transmit a radio resource allocation message to allocateradio resources to the second terminal device for an uplink transmissionin response to receiving the request for an allocation of radioresources from the first terminal device.

In accordance with some embodiments the base station is configured suchthat the request for an allocation of radio resources from the firstterminal device is received on a random access channel of the wirelesstelecommunications system.

In accordance with some embodiments the base station is configured suchthat the request for an allocation of radio resources from the firstterminal device is associated with a random access procedure of thewireless telecommunications system.

In accordance with some embodiments the base station is configured suchthat the radio resources allocated to the second terminal devicecorrespond with an allocation of radio resources requested by the firstterminal device.

In accordance with some embodiments the base station is configured suchthat the association between the first terminal device and the secondterminal device is established based on the first terminal device andthe second terminal device having a common characteristic relating totheir uplink transmissions.

In accordance with some embodiments the base station is configured suchthat the association between the first terminal device and the secondterminal device is established based on the first terminal device andthe second terminal device being associated with a same terminal deviceclassifier.

In accordance with some embodiments the base station is configured suchthat the terminal device classifier is a quality class indicator ofrespective bearers associated with the respective terminal devices.

In accordance with some embodiments the controller unit is furtherconfigured to control the transceiver to transmit an access requestdenial message to the second terminal device to instruct the secondterminal device not to make its own request for an allocation of radioresources.

In accordance with some embodiments the controller unit is furtherconfigured to control the transceiver to transmit a cease access requestdenial message to the second terminal device after having transmittedthe access request denial message to instruct the second terminal devicethat it is now allowed to make its own request for an allocation ofradio resources.

In accordance with some embodiments the controller unit is furtherconfigured to control the transceiver to transmit an access requestallow message to the first terminal device to instruct the firstterminal device that it is allowed to make the request for theallocation of radio resources.

In accordance with some embodiments the controller unit is furtherconfigured to select the first terminal device from a plurality ofterminal devices as the terminal device to which the access requestallow message is transmitted based on a transmission characteristicassociated with respective ones of the plurality of terminal devices.

In accordance with some embodiments the transmission characteristic isselected from the group comprising: a timing advance; a reference signalreceived power, a reference signal received quality, a soundingreference signal measurement at the base station, and a radio channelquality indicator.

In accordance with some embodiments the controller unit is furtherconfigured to determine an association between the first terminal deviceand a further terminal device; and to cause the transceiver to transmita radio resource allocation message to the further terminal device toallocate radio resources for an uplink transmission from the furtherterminal device based on the request for an allocation of radioresources from the first terminal device.

In accordance with some embodiments the controller unit is furtherconfigured to determine an association between the first terminal deviceand a plurality of other terminal devices and to control the transceiverto transmit an access request denial message to a subset of theplurality of other terminal devices to instruct the subset of theplurality of other terminal devices not to make their own requests foran allocation of radio resources and to further transmit radio resourceallocation messages to the plurality of other terminal devices toallocate radio resources for respective uplink transmissions fromrespective ones of the plurality of other terminal devices based on therequest for an allocation of radio resources from the first terminaldevice.

In accordance with some embodiments the transceiver is furtherconfigured to receive a transmission from the second terminal deviceusing the radio resources allocated to the second terminal device.

In accordance with some embodiments the transmission received from thesecond terminal device comprises an indication that the second terminaldevice does not require some or any of the allocated resources foruplink transmission.

In accordance with some embodiments the transmission received from thesecond terminal device comprises an indication of a request for afurther allocation of radio resources for a further uplink transmissionfrom the second terminal device.

In accordance with some embodiments the request for an allocation ofradio resources received from the first terminal device comprises arequest for an allocation of radio resources to allow the first terminaldevice to transmit a buffer status report to the base station.

In accordance with some embodiments the first and second terminaldevices are machine type communication, MTC, terminal devices.

In accordance with some embodiments the wireless telecommunicationssystem is associated with a radio interface spanning a system frequencybandwidth for supporting radio communications with a first type ofterminal device and comprising a restricted frequency bandwidth forsupporting radio communications with a second type of terminal device,wherein the restricted frequency bandwidth is narrower than and withinthe system frequency bandwidth, and wherein the first and secondterminal devices are terminal devices of the second type.

According to a third aspect of the invention there is provided awireless telecommunications system comprising the base station of thesecond aspect of the invention and a terminal device.

According to a fourth aspect of the invention there is provided a methodof operating a terminal device for receiving an allocation of radioresources for transmission of uplink data to a base station in awireless telecommunications system, the method comprising: determiningthat the terminal device has uplink data waiting for transmission to thebase station; determining that the terminal device should not transmit arequest for an allocation of radio resources for transmission of theuplink data to the base station, and waiting to receive a radio resourceallocation message from the base station to allocate radio resources tobe used for transmissions associated with the uplink data waiting fortransmission to the base station.

In accordance with some embodiments determining that the terminal deviceshould not transmit a request for an allocation of radio resourcescomprises determining that the terminal device should not initiate arandom access procedure of the wireless telecommunications system.

In accordance with some embodiments determining that the terminal deviceshould not initiate a random access procedure of the wirelesstelecommunications system comprises determining that the terminal deviceshould not make transmissions on a physical random access channel of thewireless telecommunications system.

In accordance with some embodiments determining that the terminal deviceshould not transmit a request for an allocation of radio resources isbased on the terminal device receiving an indication that the terminaldevice should not transmit a request for an allocation of radioresources.

In accordance with some embodiments the indication comprises anindication that another terminal device in the wirelesstelecommunications system has made a request for an allocation of radioresources.

In accordance with some embodiments determining that the terminal deviceshould not transmit a request for an allocation of radio resources isbased on the terminal device having received an access request denialmessage from the base station.

In accordance with some embodiments the method further comprisessubsequently receiving the radio resource allocation message from thebase station.

In accordance with some embodiments the method further comprisestransmitting the uplink data waiting for transmission to the basestation using radio resources derived from information in the radioresource allocation message received from the base station.

In accordance with some embodiments the method further comprisesdetermining at a later time after having transmitted the uplink data tothe base station that the terminal device has further uplink datawaiting for transmission to the base station, and, in response thereto,determining that the terminal device should transmit a request for anallocation of radio resources on which to transmit the uplink data tothe base station, and transmitting such a request.

In accordance with some embodiments determining that the terminal deviceshould transmit a request for an allocation of radio resources inresponse to determining that the terminal device has further uplink datawaiting for transmission to the base station is based on the terminaldevice having received an access request allow message from the basestation to indicate the terminal device is allowed to make a request foran allocation of radio resources.

In accordance with some embodiments the method further comprisesdetermining that the allocation of radio resources is not sufficient forthe uplink data waiting for transmission to the base station andtransmitting to the base station an indication of a request for afurther allocation of radio resources in response thereto.

In accordance with some embodiments the indication of a request for afurther allocation of radio resources is transmitted to the base stationusing the allocated radio resources.

In accordance with some embodiments the method further comprisestransmitting a request for an allocation of radio resources on which totransmit the uplink data to the base station after waiting to receive aradio resource allocation message from the base station for a period oftime without a radio resource allocation message being received from thebase station.

In accordance with some embodiments the terminal device is a machinetype communication, MTC, terminal device.

In accordance with some embodiments the wireless telecommunicationssystem is associated with a radio interface spanning a system frequencybandwidth for supporting radio communications with a first type ofterminal device and comprising a restricted frequency bandwidth forsupporting radio communications with a second type of terminal device,wherein the restricted frequency bandwidth is narrower than and withinthe system frequency bandwidth, and wherein the terminal device is aterminal device of the second type.

According to a fifth aspect of the invention there is provided aterminal device arranged to receive an allocation of radio resources fortransmission of uplink data to a base station in a wirelesstelecommunications system, wherein the terminal device is configured to:determine that the terminal device has uplink data waiting fortransmission to the base station; determine that the terminal deviceshould not transmit a request for an allocation of radio resources fortransmission of the uplink data to the base station, and wait to receivea radio resource allocation message from the base station to allocateradio resources to be used for transmissions associated with the uplinkdata waiting for transmission to the base station.

In accordance with some embodiments the terminal device is configuredsuch that determining that the terminal device should not transmit arequest for an allocation of radio resources comprises determining thatthe terminal device should not initiate a random access procedure of thewireless telecommunications system.

In accordance with some embodiments the terminal device is configuredsuch that determining that the terminal device should not initiate arandom access procedure of the wireless telecommunications systemcomprises determining that the terminal device should not maketransmissions on a physical random access channel of the wirelesstelecommunications system.

In accordance with some embodiments the terminal device is configuredsuch that determining that the terminal device should not transmit arequest for an allocation of radio resources is based on the terminaldevice receiving an indication that the terminal device should nottransmit a request for an allocation of radio resources.

In accordance with some embodiments the indication comprises anindication that another terminal device in the wirelesstelecommunications system has made a request for an allocation of radioresources.

In accordance with some embodiments the terminal device is configuredsuch that determining that the terminal device should not transmit arequest for an allocation of radio resources is based on the terminaldevice having received an access request denial message from the basestation.

In accordance with some embodiments the terminal device is furtherconfigured to subsequently receive the radio resource allocation messagefrom the base station.

In accordance with some embodiments the terminal device is furtherconfigured to transmit the uplink data waiting for transmission to thebase station using radio resources derived from information in the radioresource allocation message received from the base station.

In accordance with some embodiments the terminal device is furtherconfigured to determine at a later time after having transmitted theuplink data to the base station that the terminal device has furtheruplink data waiting for transmission to the base station, and, inresponse thereto, to determine that the terminal device should transmita request for an allocation of radio resources on which to transmit theuplink data to the base station, and to transmit such a request.

In accordance with some embodiments the terminal device is configuredsuch that determining that the terminal device should transmit a requestfor an allocation of radio resources in response to determining that theterminal device has further uplink data waiting for transmission to thebase station is based on the terminal device having received an accessrequest allow message from the base station to indicate the terminaldevice is allowed to make a request for an allocation of radioresources.

In accordance with some embodiments the terminal device is furtherconfigured to determine that the allocation of radio resources is notsufficient for the uplink data waiting for transmission to the basestation and to transmit to the base station an indication of a requestfor a further allocation of radio resources in response thereto.

In accordance with some embodiments the terminal device is configuredsuch that the indication of a request for a further allocation of radioresources is transmitted to the base station using the allocated radioresources.

In accordance with some embodiments the terminal device is furtherconfigured to transmit a request for an allocation of radio resources onwhich to transmit the uplink data to the base station after waiting toreceive a radio resource allocation message from the base station for aperiod of time without a radio resource allocation message beingreceived from the base station.

In accordance with some embodiments the terminal device is a machinetype communication, MTC, terminal device.

In accordance with some embodiments the wireless telecommunicationssystem is associated with a radio interface spanning a system frequencybandwidth for supporting radio communications with a first type ofterminal device and comprising a restricted frequency bandwidth forsupporting radio communications with a second type of terminal device,wherein the restricted frequency bandwidth is narrower than and withinthe system frequency bandwidth, and wherein the terminal device is aterminal device of the second type.

According to a sixth aspect of the invention there is provided awireless telecommunications system comprising the terminal device of thefifth aspect of the invention and a base station.

It will be appreciated that features and aspects of the inventiondescribed above in relation to the first and other aspects of theinvention are equally applicable to, and may be combined with,embodiments of the invention according to other aspects of the inventionas appropriate, and not just in the specific combinations describedabove.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments of the present invention will now be described by way ofexample only with reference to the accompanying drawings where likeparts are provided with corresponding reference numerals and in which:

FIG. 1 schematically represents an example of a conventional LTE-typewireless telecommunication network;

FIG. 2 schematically represents a conventional random access procedurein a LTE-type wireless telecommunication network;

FIG. 3 schematically represents some aspects of a conventional uplinkradio frame structure in a LTE-type wireless telecommunication network;

FIG. 4 shows a table summarizing four potential formats in which aterminal device may transmit a random access preamble in accordance witha LTE-based network operating in a frequency division duplex (FDD) mode;

FIG. 5 schematically represents an example of a LTE-type wirelesstelecommunication network according to an embodiment of the invention;and

FIG. 6 schematically represents a scheme for allocating radio resourcesin a LTE-type wireless telecommunication network in accordance with anembodiment of the invention.

DESCRIPTION OF EXAMPLE EMBODIMENTS

FIG. 1 provides a schematic diagram illustrating some basicfunctionality of a wireless telecommunications network/system 100operating in accordance with LTE principles. Various elements of FIG. 1and their respective modes of operation are well-known and defined inthe relevant standards administered by the 3GPP (RTM) body and alsodescribed in many books on the subject, for example, Holma H. andToskala A [2]. The network 100 includes a plurality of base stations 101connected to a core network 102. Each base station provides a coveragearea 103 (i.e. a cell) within which data can be communicated to and fromterminal devices 104. Data is transmitted from base stations 101 toterminal devices 104 within their respective coverage areas 103 via aradio downlink. Data is transmitted from terminal devices 104 to thebase stations 101 via a radio uplink. The radio downlink and radiouplink may together be considered to support the radio interface for thewireless telecommunications system. The core network 102 routes databetween the respective base stations 101 and provides functions such asauthentication, mobility management, charging and so on. As is wellunderstood, terminal devices may also be referred to as mobile stations,user equipment (UE), user terminal, mobile radio, and so forth, and basestations may also be referred to as transceiverstations/nodeBs/e-NodeBs/eNBs, and so forth.

In LTE-type networks scheduling decisions for both uplink (UL) anddownlink (DL) transmissions are governed by a scheduler in the basestation (eNodeB/eNB). For downlink, clearly the base station knows howmuch data is ready to be delivered to each terminal device. However, foruplink the base station is generally not initially aware of how muchdata needs to be communicated (and hence does not know how much radioresource needs to be allocated) because the data is buffered at therespective terminal devices. Consequently, in accordance withestablished LTE principles, terminal device are configured tocommunicate to their serving base station information regarding theirbuffer status (i.e. how much data the respective terminal devices haveready for uplink communication). This information is conventionally sentin a so-called Buffer Status Report (BSR) on an uplink shared channel(UL-SCH) which is physically transmitted on a physical uplink sharedchannel (PUSCH). Further information on BSRs can be found with referenceto the relevant standards. See, for example, ETSI TS 136 321 V10.6.0(2012 October)/3GPP TS 36.321 version 10.6.0 Release 10 [3]

A BSR in a conventional LTE network is 6 bits long and a terminal devicemay send either one or four such BSRs at a time, reporting the number ofbytes of data in either one group of logical channels or four groups oflogical channels respectively. The 6 bits are quantized in the relevantspecifications/standards to allow a terminal device to report bufferlevels of between 0 and 150,000 bytes, or in the case of an extendedBSR, between 0 and 3,000,000 bytes. A terminal device will have a RadioResource Control (RRC) configuration determining whether it should sendordinary or extended BSRs.

A BSR can be Regular, Periodic or Padding.

A terminal device sends a Regular BSR when:

a) Data arrives for a logical channel which has higher priority than thelogical channels whose buffers previously contained data;

b) Data becomes available for any logical channel when there waspreviously no data available for transmission;

c) A ‘retxBSR’ timer expires and there is data available fortransmission.

The retxBSR timer is used to alleviate the situation where the basestation fails to receive BSR correctly but for some reason is not ablesuccessfully to inform the terminal device of this (perhaps because theBSR NACK is incorrectly decoded as ACK at the terminal device).Therefore, the retxBSR timer is reset each time an UL grant is receivedand BSR is transmitted when the timer expires.

A Periodic BSR is sent when a periodicBSR timer expires and is used byRRC to control BSR reporting.

A Padding BSR is sent when there is space available in a Medium AccessControl Protocol Data Unit (MAC PDU) that can accommodate a BSR.

In accordance with conventional LTE principles, if a terminal devicedoes not have a sufficient allocation of PUSCH resource to send aRegular BSR, it will instead attempt to send a one-bit SchedulingRequest (SR) on a physical uplink control channel (PUCCH) in resourceswhich can be allocated by RRC. If the terminal device does not have suchan allocation, it will initiate a Random Access (RA) procedure in whichit sends a SR to request an uplink (UL) grant of resources on PUSCHwhich are sufficient to send the BSR. Periodic and Padding BSR do nottrigger SR (or RA).

Random Access procedures in LTE-based networks can be contention basedor non-contention based. A contention based RA procedure is triggeredwhen a terminal device needing to send a BSR does not have a sufficientallocation of PUSCH resource to do so or any SR allocation on PUCCH.Random Access procedures generally involve accessing a random accesstransport channel (RACH in LTE terminology) with transmissions on anassociated physical random access channel (PRACH in LTE terminology).

To access RACH in a LTE-type network, a terminal device transmits asequence, known as a preamble, using defined radio resources within thenetwork's uplink radio frame structure (time-frequency resource grid).The base station is configured to monitor the defined resources for anyof the preambles that a terminal device in the cell might transmit, and,on detecting such a preamble, responds in accordance with the defined RAprocedure, which is summarized further below. In total, 838 preamblesare defined in LTE, but currently a network operator configures eachcommunication cell with only 64 preambles according to thecharacteristics of the cell. The preambles and the uplink resources fortransmission of the preambles available for use in a particularcommunication cell are broadcast by the base station to the terminaldevices with System Information Block (SIB) signalling, in particular,using SIB2.

FIG. 2 is a ladder diagram schematically showing steps of a conventionalLTE contention-based random access procedure in which a terminal device104 (left-hand node in FIG. 2) seeks to access to a base station 101(right-hand node in FIG. 2). For more details on LTE RA procedures see,for example, ETSI TS 136 300 V10.8.0 (2012 July)/3GPP TS 36.300 version10.8.0 Release 10 [4].

The steps of the contention-based RA procedure may be summarized asfollows:

Step 1. The terminal device 104 transmits a preamble from among the setconfigured for contention based RA in the communication cell served bythe base station 101. Based on the radio resources used for thetransmission the terminal device determines a RA-RNTI (Random AccessRadio Network Temporary Identity) associated with the transmission.

Step 2. The base station 101 sends a Random Access Response (RAR)addressed to RA-RNTI and containing the identity of the detectedpreamble, a timing alignment command and a temporary C-RNTI (Cell RadioNetwork Temporary Identity).

Step 3. Assuming the terminal device receives the RAR from the basestation within a specified time window after preamble transmission inStep 1, the terminal device transmits a so-called Message 3, whichcontains the appropriate RA procedure message. For example, the RAprocedure message might be a scheduling request, a tracking area updateor a RRC connection request.

Step 4. On receiving Message 3 from Step 3, the base station sends acontention resolution message. The terminal device to which this messageis addressed will transmit ACK/NACK response signalling in associationwith the defined HARQ (Hybrid Automatic Repeat request) procedures.Other contending terminal devices which successfully decode the messageas a result of contention transmit no

HARQ feedback and exit the RA procedure.

The physical transmissions associated with the RA procedure in LTE-basednetworks are carried on PRACH. This physical channel occupies abandwidth of 1.08 MHz (falling within the width of 6 Resource blocks(RBs)) in the frequency domain and, unlike other aspects of LTEchannels, employs a 1.25 kHz subcarrier spacing. The subframes of theuplink radio frame structure in which terminal devices are permitted totransmit PRACH are configurable per-cell by the network operator. PRACHis time- and frequency-multiplexed with PUSCH and PUCCH as schematicallyindicated in FIG. 3.

FIG. 3 represents a time-frequency resource grid for a LTE-based uplinkframe structure with a schematic indication of how PUSCH, PUCCH andPRACH are multiplexed. As can be seen from FIG. 3, PUCCH is associatedwith frequency resources towards the upper and lower edges of the systembandwidth; PUSCH is associated with frequency resources between thePUCCH regions; and PRACH is associated with discrete regions ofresources within the PUSCH regions. The respective regions of time andfrequency resources associated with PRACH occur once every PRACH slotperiod, and as noted above, have a bandwidth corresponding to 6RBs.Whether PUSCH transmissions occur in PRACH slots is a matter for thebase station scheduler.

FIG. 4 is a table that summarizes the four potential formats in which aterminal device may transmit a RA preamble in Step 1 of FIG. 2 inaccordance with a LTE-based network operating in a frequency divisionduplex (FDD) mode. The left-most column (“Preamble format”) lists thefour potential preamble formats. The next column (“T_(CP)”) lists thecorresponding cyclic prefix duration in microseconds. The next column(“T_(SEQ)”) lists the corresponding preamble sequence duration inmicroseconds. The next column (“T_(GT)”) lists the corresponding guardtime in microseconds. The right-most column (“PRACH slot duration”)lists the corresponding duration of each PRACH slot in subframes.

A significant aspect of PRACH in LTE-type networks is that resources forPRACH transmissions extend for at least one subframe, and potentiallylonger for preamble formats 1 to 3, and occur at the same time as PUSCHand PUCCH transmissions. This means PRACH is a potential source ofinterference for PUSCH and PUCCH during times of overlappingtransmissions. In accordance with some embodiments of the invention thepotential for interference caused by PRACH transmissions may be reducedby providing for modified random access procedures as discussed furtherbelow.

Interference associated with random access procedure transmissions canoccur regardless of a wireless telecommunication's system bandwidth, butthe issue can be expected to be relatively more significant insituations involving relatively narrow bandwidths. This is because thebandwidth of the PRACH channel can becomes a relatively larger part ofthe overall system bandwidth. In this respect, one area where PRACHtransmissions could represent a particularly significant interferenceissue is in the use of the so-called virtual carrier networks, forexample as discussed in co-pending UK patent applications numbered GB1101970.0 [5], GB 1101981.7 [6], GB 1101966.8 [7], GB 1101983.3 [8], GB1101853.8 [9], GB 1101982.5 [10], GB 1101980.9 [11], GB 1101972.6 [12],GB 1121767.6 [13] and GB 1121766.8 [14]. More information on virtualcarriers can be found from these documents, but by way of a generaloverview, the concept underlying the virtual-carrier ideas is the use ofa relatively narrow band of frequencies from within a wider host carrierbandwidth to support terminal devices operating within the narrowerband. Thus, the narrower band within the host carrier may in somerespects be considered as a separate carrier for supporting certaindevices (i.e. virtual carrier).

As noted above, certain classes of devices, such as MTC devices, supportcommunication applications that can often be characterised by thetransmission of small amounts of data at relatively infrequentintervals, and can thus operate with considerably less complexity thanconventional LTE terminals. In many scenarios, providing low capabilityterminals such as those with a conventional high-performance LTEreceiver unit capable of operating over a full system bandwidth can beoverly complex for a device which only needs to communicate smallamounts of data. This may therefore limit the practicality of awidespread deployment of low capability MTC type devices in a LTEnetwork if the devices are required to support relatively complextransceivers. It is preferable instead to provide low capabilityterminals such as MTC devices with a simpler transceiver unit which ismore proportionate with the amount of data likely to be transmitted tothe terminal. In this regard, the provision of a relatively narrow band“virtual carrier” within the transmission resources of a conventionalOFDM type downlink carrier (i.e. a “host carrier”) can allow deviceswith simpler transceivers to be accommodated. This is because datacommunicated on the virtual carrier can be received and decoded withoutneeding to process the full bandwidth of the downlink host OFDM carrier.Accordingly, data communicated on the virtual carrier can be receivedand decoded using a reduced complexity transceiver unit, which, as notedabove, is attractive for MTC type devices.

One proposed bandwidth for virtual carrier operation is 1.4 MHz and thiscorresponds with the bandwidth for PRACH. Accordingly, it may be thecase in a virtual carrier context that PRACH transmissions span, andhence potentially interfere with, the full bandwidth for PUSCHtransmissions on the virtual carrier, possibly for up to 3 subframes(depending on preamble format), when a terminal device initiates a RAprocedure. The PRACH transmissions may also interfere with PUCCHdepending on scheduling.

Accordingly, it is expected that narrow bandwidth carriers, such asvirtual carriers operating within a wider bandwidth host carrier, may bemost affected by PRACH transmissions associated with random accessprocedures resulting in a degradation in performance for PUSCH and PUCCHtransmissions. Such a degradation in performance can be expected toresult in increased need for retransmissions from terminal devices,thereby causing still further congestion and interference on the radionetwork, and consuming terminal device power reserves more quickly.Furthermore, as noted above, for MTC-type devices, where terminaldevices may be more densely deployed, such PRACH to PUSCH/PUCCHinterference could arise even more frequently as a result of theterminal device density. Such MTC devices are designed to be low costand may have limited battery life and transmit power, and be installedin inaccessible locations, and so it can be particularly desirable tominimize the need to retransmit PUSCH/PUCCH due to PRACH interference inrespect of MTC-devices, and furthermore in respect of MTC-type devicesoperating on relatively narrow bandwidths, such as in a virtual carriercontext. Nonetheless, it will be appreciated that PRACH to PUSCH/PUCCHinterference issues can equally arise for more conventional types ofterminal device operating on wider bandwidths.

In addition to radio network interference, in situations where there isthe potential for relatively large numbers of terminal devices to seekto access a network through random access procedures the limited numberof available RA preambles may become an issue. This is because with moreterminal devices seeking access around the same time there is anincreased likelihood of two terminal devices choosing the same RApreamble and causing a collision on RACH. Such collisions also result inPRACH retransmissions from at least one of the colliding terminaldevices, thereby causing more radio network interference and consumingadditional power for the terminal device.

With these issues in mind, certain embodiments of the invention aredirected to schemes for controlling random access procedures for aplurality of terminal devices in a wireless telecommunications networkwith a view to reducing the overall number of PRACH transmissionsoccurring. In some examples this is achieved by a base stationallocating uplink resources to one terminal device in response to arandom access procedure initiated by another, different, terminaldevice. Correspondingly, in accordance with some embodiments a terminaldevice may receive an allocation of resources as a consequence ofanother terminal device initiating a random access procedure.

FIG. 5 schematically shows a telecommunications system 500 according toan embodiment of the invention. The telecommunications system 500 inthis example is based broadly on a LTE-type architecture. As such manyaspects of the operation of the telecommunications system 500 are knownand understood and are not described here in detail in the interest ofbrevity. Operational aspects of the telecommunications system 500 whichare not specifically described herein may be implemented in accordancewith known techniques, for example according to the established andpublished LTE-standards.

The telecommunications system 500 comprises a core network part (evolvedpacket core) 501 coupled to a radio network part. The radio network partcomprises a base station (evolved-NodeB/eNB) 502 adapted in accordancewith an embodiment of the invention and arranged to communicate with aplurality of terminal devices. In this example, four terminal devicesare shown, namely a terminal device 505 of a first type and threeterminal devices 508A, 508B, 508C of a second type. Where it is notsignificant to distinguish between the three terminal devices 508A,508B, 508C of the second type, these terminal devices may be referred tocollectively as terminal devices 508. It will of course be appreciatedthat in practice the radio network part may comprise a plurality of basestations serving a larger number of terminal devices across variouscommunication cells. However, only a single base station and fourterminal devices are shown in FIG. 5 in the interests of simplicity.

As with a conventional mobile radio network, the terminal devices 505,508 are arranged to communicate data to and from the base station(transceiver station) 502. The base station is in turn communicativelyconnected to a serving gateway, S-GW, (not shown) in the core networkpart which is arranged to perform routing and management of mobilecommunications services to the terminal devices in thetelecommunications system 500 via the base station 502. In order tomaintain mobility management and connectivity, the core network part 501also includes a mobility management entity (not shown) which manages theenhanced packet service, EPS, connections with the terminal devices 505,508 operating in the communications system based on subscriberinformation stored in a home subscriber server, HSS. Other networkcomponents in the core network (also not shown for simplicity) include apolicy charging and resource function, PCRF, and a packet data networkgateway, PDN-GW, which provides a connection from the core network part501 to an external packet data network, for example the Internet. Asnoted above, the operation of the various elements of the communicationssystem 500 shown in FIG. 5 may be broadly conventional apart from wheremodified to provide functionality in accordance with embodiments of theinvention as discussed herein.

In this example, it is assumed the first terminal device 505 is aconventional smart-phone type terminal device communicating with thebase station 502 in a conventional manner. This first terminal device505 comprises a transceiver unit 507 for transmission and reception ofwireless signals and a controller unit 506 configured to control thesmart phone 505. The controller unit 506 may comprise a processor unitwhich is suitably configured/programmed to provide the desiredfunctionality using conventional programming/configuration techniquesfor equipment in wireless telecommunications systems. The transceiverunit 507 and the controller unit 506 are schematically shown in FIG. 5as separate elements. However, it will be appreciated that thefunctionality of these units can be provided in various different ways,for example using a single suitably programmed integrated circuit. Aswill be appreciated the smart phone 505 will in general comprise variousother elements associated with its operating functionality.

In this example, it is assumed the terminal devices 508 the second typeare all machine-type communication (MTC) terminal devices. As discussedabove, these types of device may be typically characterised assemi-autonomous or autonomous wireless communication devicescommunicating small amounts of data. Examples include so-called smartmeters which may be located in a customer's house and periodicallytransmit information back to a central MTC server data relating to thecustomer's consumption of a utility, such as gas, water, electricity andso on.

As with the smart phone 505, the respective MTC devices 508A, 508B, 508Ceach comprise a transceiver unit 510A, 510B, 510C for transmission andreception of wireless signals and a controller unit 509A, 509B, 509Cconfigured to control the respective devices 508A, 508B, 508C. Thecontroller units 509A, 509B, 509C may each comprise various sub-unitsfor providing functionality in accordance with embodiments of theinvention. For example, in accordance with some embodiments therespective terminal devices may comprise a data for uplink determiningunit for determining the terminal device has uplink data waiting fortransmission to the base station and a transmit request determining unitfor determining the terminal device should not transmit a request for anallocation of radio resources for transmission of the uplink data to thebase station and instead should wait to receive a radio resourceallocation message from the base station configured to operate toprovide functionality as described herein in accordance with embodimentsof the invention. These sub-units may be implemented as discretehardware elements or as appropriately configured functions of thecontroller unit. Thus the respective controller units 509A, 509B, 509Cmay comprise a processor unit which is suitably configured/programmed toprovide the desired functionality described herein using conventionalprogramming/configuration techniques for equipment in wirelesstelecommunications systems. The respective pairs of transceiver units510A, 510B, 510C and controller units 509A, 509B, 509C for each device508 are schematically shown in FIG. 5 as separate elements for ease ofrepresentation. However, it will be appreciated that within each devicethe functionality of these units can be provided in various differentways following established practices in the art, for example using asingle suitably programmed integrated circuit. It will be appreciatedthe MTC devices 508 will in general comprise various other elementsassociated with their operating functionality and these other elementsmay generally operate in accordance with conventional techniques.

The base station 502 comprises a transceiver unit 503 for transmissionand reception of wireless signals and a controller unit 504 configuredto control the base station 502. The controller unit 504 may againcomprise various sub-units for providing functionality in accordancewith embodiments of the invention. For example, in accordance with someembodiments the base station may comprise: a request receiving unit forreceiving a request for an allocation of radio resources from a firstterminal device; an association determining unit for determining anassociation between the first terminal device and a second terminaldevice; and an allocation message transmitting unit for transmitting aradio resource allocation message to allocate radio resources to thesecond terminal device for an uplink transmission in response toreceiving the request for an allocation of radio resources from thefirst terminal device configured to operate to provide functionality asdescribed herein in accordance with embodiments of the invention. Thesesub-units may be implemented as discrete hardware elements or asappropriately configured functions of the controller unit/transceiverunit. Thus, the controller unit 504 may comprise a processor unit whichis suitably configured/programmed to provide the desired functionalitydescribed herein using conventional programming/configuration techniquesfor equipment in wireless telecommunications systems. The transceiverunit 503 and the controller unit 504 are schematically shown in FIG. 5as separate elements for ease of representation. However, it will beappreciated the functionality of these units can be provided in variousdifferent ways following established practices in the art, for exampleusing a single suitably programmed integrated circuit. It will beappreciated the base station 502 will in general comprise various otherelements associated with its operating functionality and these otherelements may generally operate in accordance with conventionaltechniques.

It is assumed here the base station 502 is configured to communicatewith the smart phone 505 in accordance with the established principlesof LTE-based communications and to communicate with the terminal devices508 in accordance with embodiments of the invention as described herein.

Certain embodiments of the invention are based on a recognition thatcertain types of terminal device in a wireless telecommunicationsnetwork, such as the network 500 in FIG. 5, can be expected to havesimilar traffic profiles. For example, MTC-type terminal devices 508associated with a given MTC application, such as smart metering onbehalf of a particular gas supplier, might all be expected to beconfigured to uplink similar amounts of data at similar times, forexample corresponding to a regular upload of information relating to auser's consumption of gas (or whatever it is that is being metered). Inthis regard, certain types of terminal device may be grouped accordingto their expected (or historically seen) traffic profiles. For example,the terminal devices might be grouped together based on an associatedQuality of Service (QoS) Class Indicator (QCI) as specified in existingLTE standards (see, for example, ETSI TS 123 401 V10.8.0 (2012July)/3GPP TS 23.401 version 10.8.0 Release 10 [15] and ETSI TS 123 203V10.7.0 (2012 July)/3GPP TS 23.203 version 10.7.0 Release 10 [16]. Inaccordance with embodiments of the invention in which terminal devicesare grouped based on QCI, it will be appreciated there may be someexpansion of the currently specified QCI categories, for example toinclude categories relating to typical periodicity of uplink traffic, orburst parameters/statistics. Terminal devices may be grouped in otherways. For example, MTC devices associated with a common MTC application,for example smart metering on behalf of a particular gas supplier, maybe considered to fall into a single traffic-profile group.

Thus, in accordance with an embodiment of the invention, a plurality ofterminal devices may be notionally categorized as belonging to aparticular group having some common characteristics associated with theuplink traffic profiles. With reference to FIG. 5, it is assumed in thisexample the three MTC-type terminal devices 508A, 508B, 508C arecategorized as forming a group of terminal devices with similar uplinktraffic profiles. As noted above, this might be because all three MTCterminal devices are associated with a given MTC application. In thefollowing description of various modes of operation in accordance withsome embodiments of the invention it will be assumed the MTC devices arein a RRC_Connected state.

In accordance with a first embodiment, it is assumed a base stationmaintains a record of the terminal devices in the same traffic profilegroup (for example based on a data record containing a list ofidentifiers for the respective terminal devices in the respective groupsserved by the base station). However, while the base station is aware ofthe relevant grouping information, in accordance with this exampleembodiment the individual terminal devices are not aware of theidentities of other members of the group(s) to which they belong.

Referring again to FIG. 5, it is assumed that at some point in timeterminal device 508A finds itself with some data in its uplink buffer.This might be because the terminal device is associated with a smartmeter and it is time to upload information relating to usage accordingto its operating schedule. In accordance with the conventionalprinciples of LTE operation, such as described above, the terminaldevice 508A seeks to transmit a BSR to the base station 502 to requestan uplink allocation on PUSCH to uplink the data in its buffer in thenormal way. However, again as described above, it may be that theterminal device has no current uplink grant on PUSCH on which to send aBSR and insufficient resources on PUCCH to send a SR. Accordingly, theterminal device will fall back to seek to access the network via RACHand the RA procedure. In this respect, the terminal device may followconventional principles to arrive at the situation in which the RAprocedure may be invoked in accordance with the conventional operatingprinciples of the network in which this example embodiment isimplemented.

FIG. 6 is a ladder diagram schematically showing signalling among thebase station 502 and terminal devices 508A, 508B, 508C in FIG. 5 inaccordance with an embodiment of the invention. The signallingrepresented in FIG. 6 starts from a point at which terminal device 508Ahas reached a state in which a desire to send a BSR has caused terminaldevice 580A to initiate a RA procedure.

In accordance with this embodiment of the invention, the RA procedure inrespect of terminal device 508A is configured to proceed as normal, forexample as described above with reference to FIG. 2. Thus, in a firststep the terminal device 508A sends a conventional RA preamble 601A tothe base station 502 and, in a second step, the base station 502responds by sending a conventional RAR 602A to the terminal device 508A.The terminal device 508A in turn transmits a Message 3 603A of theconventional RA procedure to the base station 502 in accordance with theprinciples discussed above with reference to FIG. 2.

At this stage of the process represented in FIG. 6 the base station 502therefore receives signalling corresponding to Message 3 in theconventional RA procedure which indicates the terminal device 508A istransmitting a SR to request PUSCH resources to transmit a Regular BSR.In accordance with certain embodiments of the invention, the basestation 502 is configured to determine whether or not the terminaldevice 508A that has initiated a RA procedure is a member of a definedtraffic profile group. In this example this leads the base station toidentify terminal devices 508B and 508C as being classified as havingsimilar traffic profiles to terminal device 508A currently involved inthe RA procedure. Because of their similar traffic profiles, it may beexpected that, as with terminal device 508A, the terminal devices 508Band 508C will also be approaching a state in which they will wish toinvoke their own RA procedures to request uplink resources to transmittheir own BSRs. However, in accordance with some embodiments of theinvention the base station 502 is configured to act to prevent terminaldevices 508B, 508C from making such requests for uplink resources. Thisis done in this example by the base station 502 instructing the terminaldevices 508B, 508C to not make any PRACH transmissions by transmittingexplicit signalling comprising what may be referred to in accordancewith embodiments of the invention as PRACH access denial (or accessrequest denial) messages 604B, 604C. That is to say, once the basestation receives PRACH transmissions associated with a RA procedure forone terminal device in a group of terminal devices deemed to havetraffic profiles with some common characteristic(s), the base station isconfigured to send signalling to the other terminal devices in the groupto indicate they are denied access to PRACH, at least temporarily,thereby preventing these other terminal devices in the group frominitiating their own RA procedures.

Thus, a terminal device receiving a PRACH access denial messageaccording to an embodiment of the invention, such as the terminaldevices 508B, 508C in FIG. 6, will not initiate its own random accessprocedure by sending a random access preamble, even if in accordancewith the terminal device's normal operating procedures it wouldotherwise be ready to invoke a random access procedure. For example, ifeither one of the terminal devices 508B, 508C reach a state in whichthey are ready to initiate a random access procedure to request anuplink radio resource allocation to allow them to send a BSR to the basestation, they will not do so if they have been denied PRACH access (e.g.through a PRACH access denial message 604B, 604C) if the denial has notyet been lifted. By way of example, the PRACH access denial signallingcould be implemented by way of a flag asserted or message contained in aRRC (re)configuration transmitted via the usual means of a PDCCHaddressed to the C-RNTI(s) of the relevant terminal device(s) forlocating the RRC message on PDSCH. Alternatively, PRACH access denialmessaging could be conveyed using an additional bit (flag) asserted or afield added in a DCI (Downlink Control Information) message carried on aPDCCH addressed to the relevant terminal devices' C-RNTIs.

Thus, having received the respective PRACH access denial messages 604B,604C, the terminal devices 508B, 508C do not initiate any RA proceduresof their own, even if they would otherwise have done so. Instead theterminal devices 508B, 508C that have been denied PRACH access wait toreceive further communications from the base station, as describedfurther below.

Turning now to the communications between the base station 502 and theterminal device 508A which initiated the RA procedure, the base station502 having received the scheduling request (SR) from the terminal device508A in Message 3 603A proceeds to send a contention resolution message605A to the terminal device 508A, again following conventional RAprocedures in respect of the communications associated with the RAprocedure initiated by the terminal device 508A.

Again following the conventional LTE signalling procedures associatedwith the transmission of a BSR, the base station 502 proceeds totransmit to the terminal device 508A an uplink grant for BSR message606A providing an uplink grant of radio resources on which the terminaldevice 508A is to transmit its buffer status report.

Having received the uplink grant of radio resources for transmitting itsBSR, the terminal device 508A proceeds to transmit a BSR message 607Acomprising the BSR to the base station 502.

On receiving the BSR message 607A from the terminal device 508A the basestation 502, more particularly, a scheduler of the base station 502,determines an allocation of radio resources to grant to the terminaldevice 508A to allow the terminal device 508A to transmit the data ithas buffered and ready for uplink to the base station 502, andcommunicates this uplink resource allocation to the terminal device 508Ain a buffered data uplink grant message 608A. Subsequently, although notshown in FIG. 6, the terminal device 508A can transmit the buffered datato the base station 502 using the uplink radio resources allocated tothe terminal device 508A through the buffered data uplink grant message608A.

Accordingly, the communications between the base station 502 and theterminal device 508A which initiated the RA procedure as represented inFIG. 6 can be generally conventional. For example, the varioussignalling messages between the terminal device 508A and the basestation 502 may be made in accordance with the established principles ofLTE-type network communications. For example, the uplink grant messages605A, 607A may be made in the usual way using a physical downlinkcontrol channel (PDCCH).

However, a significant aspect of the operation represented in FIG. 6 inaccordance with an embodiment of the invention which differs fromconventional approaches is that the base station 502 is configured toalso send uplink grant messages 608B, 608C to the terminal devices 508B,508C which have not themselves requested uplink resources, and indeedhave been denied PRACH access as discussed above to prevent them frombeing able to request resources. The amount of radio resources allocatedto the terminal devices 508B, 508C in this way may correspond with theamount of radio resources allocated to the terminal device 508A whichinitiated the random access procedure according to the buffer statusreport received from that terminal device 508A. The uplink grantmessages 608B, 608C may be sent to the terminal devices 508B, 508C inaccordance with the established principles for granting uplink resourcesin LTE-type wireless telecommunications systems, for example using PDCCHsignalling in the usual way. A scheduler in the base station 502 mayoperate to allocate the radio resources to the various terminal devices508A, 508B, 508C in accordance with the established principles thatwould be applied had the base station received independent buffer statusreports from the respective terminal devices. For example, uplink grantsignalling 608A, 608B, 608C may be provided over a number of radiosubframes, depending on the amount of data for uplink based on the BSRreceived from the first terminal device 508 in the BSR message 607A inFIG. 6 and the radio resource availability in the cell, etc.

Thus, an underlying principle of this mode of operation is that the basestation 502 has associated the terminal device 508A as being a member ofa group of terminal devices previously identified as having similartraffic profiles, wherein the group in this example further includesterminal devices 508B, 508C. Thus, the base station allocates radioresources (“grants”) for subsequent uplink transmissions from theterminal devices 508B, 508C on the basis of having received a requestfor an allocation of resources for an uplink transmission from anotherterminal device 508A in the group. The principle here is that if theterminal device 508A has a particular amount of data to transmit to thebase station, it may reasonable to expect other terminal devices 508B,508C in the same group may have a similar amount of data to transmit tothe base station. Accordingly, the base station can pre-emptivelyallocate resources to the terminal devices 508B, 508C without themhaving requested such resources. Indeed, in accordance with thisembodiment of the invention, the terminal devices 508B, 508C areprevented from asking for resources by virtue of the base station havingtold them not to through the PRACH access denial messages 604B, 604Cdiscussed above.

Accordingly, this approach in accordance with some embodiments of theinvention provides a mechanism for a base station to provide resourceallocations to multiple terminal devices in response to a resourcerequest from a single terminal device. An advantage of this approach ofpredicting when certain terminal devices may have data for uplink basedon requests for uplink resources received from another terminal device,and allocating radio resources accordingly, is a potential reduction inthe number of requests for resources received by the base station. Thiscan therefore help to reduce the potential for radio interference andcongestion in the communication cell served by the base station, inparticular in association with random access procedures. In somerespects approaches in accordance with embodiments of the invention maythus be seen as providing for pre-emptive resource allocations inrespect of terminal devices which have not requested resources, butwhich have been classified as having a common traffic profilecharacteristic with another terminal device which has requested uplinkresources. The other terminal device which has requested uplinkresources in accordance with this example embodiment is simply the firstterminal device of the group to initiate a random access procedurethrough sending a random access preamble to the base station. In thisrespect, the first terminal within a group of terminal devices whichinitiates a random access procedure may in effect be considered tobecome the “master” terminal device or “delegate” terminal device forthe group of terminal devices in respect of providing a buffer statusreport to the base station which the base station will treat as beingapplicable for all terminal devices in the group and allocate radioresources accordingly.

Having received the uplink grant messages 608B, 608C, the respectiveterminal devices 508B, 508C may thus transmit any data they have intheir buffers to the base station using the allocated resources.

In some cases it may be that the amount of resources allocated to theterminal devices 508B, 508C directly match, or exceed, the amount ofdata the respective terminal devices have waiting in their buffers foruplink transmission. For example this might be the case if there is aclose correspondence between the traffic profiles of the terminal device508A initiating the random access procedure and the other terminaldevices 508A, 508C in the group. For example, this might be expected insituations where the various terminal devices are performingcorresponding tasks. For example if each terminal device is associatedwith a smart-meter configured to record usage data in the same way, andto report the usage data to a server application at roughly the sametime, it may be expected that all terminal devices will have verysimilar amounts of data in the buffer at around the same times. In thiscase, the terminal devices 508B, 508C may proceed to uplink theirbuffered data using the resources they have been allocated in the usualway.

However, in other cases, it may be that in fact one or more of theterminal devices 508B, 508C which have been pre-emptively allocatedresources by the base station 502 do not currently have any buffereddata for uplink. This can arise even within an identified group ofterminal devices having generally similar traffic profiles, for examplebecause the traffic profiles are not identical, or because the terminaldevice 508A initiating the random access procedure did so for a reasonthat does not apply to the other terminal devices. For example, theterminal device 508A in FIG. 6 may have initiated the random accessprocedure to transmit uplink data associated with a fault condition thathas arisen rather than to uplink data associated with its normal trafficprofile on the basis of which it has been classified as being groupedwith the other terminal devices.

In some other cases it may be that in fact one or more of the terminaldevices 508B, 508C which have been pre-emptively allocated resources bythe base station 502 require more resources than they have beenallocated to transmit all the data they currently have buffered foruplink.

When a terminal device is pre-emptively allocated uplink resources thateither it does not need, or which are not sufficient for its needs, theterminal device may in accordance with some embodiments of the inventionbe configured to send a rejection/insufficiency indication message 609B,609C to the base station 502 to indicate this fact. Arejection/insufficiency indication message 609B, 609C may be transmittedby the terminal device 508B, 508C using the resources it has beenallocated for uplink through the uplink grant messages 608B, 608Cpreviously received from the base station 502, for example.

A base station 502 receiving a rejection/insufficiency indicationmessage from a terminal device can take appropriate scheduling action.

For example, in response to a rejection indication message (i.e. amessage indicating the terminal device does not have any data for uplinkand so in effect rejects the grant) the base station may avoid furtherscheduling for the terminal device.

Conversely, for an insufficiency indication message, the base stationmay allocate further resources to the terminal device, for example toallow the terminal device to transmit a buffer status report so thatfurther resources can be allocated accordingly, or the base station maysimply allocate more uplink resources to the terminal device in one ormore subsequent subframe(s) to allow the terminal device to empty itsbuffers.

In this respect, it may be helpful in some implementations if a terminaldevice transmitting an insufficiency indication message is configured tocommunicate an indication of how much resource is currently desired. Forexample, the terminal device may be configured to transmit as aninsufficiency indication message a buffer status report. Thus, a basestation receiving a BSR on radio resources pre-emptively allocated to aterminal device may be configured to respond by recognising this is arequest for more resources to be allocated, and allocate these resourcesaccordingly. Once the base station has identified the extra resourceallocation is requested, the allocation may be made in the usual way. Ina variant of this approach a terminal device may instead of transmittinga conventional BSR, transmit what might be termed a differential BSRindicating a difference in an amount of resource between the amount thatwas allocated by the base station and a desired amount.

In situations where a base station identifies a terminal device in aparticular group does not require resources that it has beenpre-emptively allocated on the basis of a request from another terminaldevice, or requires more resources than it has been pre-emptivelyallocated, the base station may be configured to take account of thisand modify the terminal device groupings accordingly. For example, aterminal device which is found to repeatedly not require resources, orrequire more resources than its fellow group members, might be removedfrom the group on the basis that its traffic profile is not sufficientlysimilar to the traffic profile of other terminal devices in the group tomerit the above-described approach of pre-emptive resource allocations.Such a terminal device may be moved to another group, or simply removedfrom any groups associated with pre-emptive resource allocationprocesses in accordance with embodiments of the invention.

When the base station has allocated resources to all terminal devices ina group, including the allocation to the delegate terminal device 508Aof the radio resources it has requested and the correspondingallocations to other terminal devices in the delegate terminal device'sgroup, it may be appropriate for the bar on accessing PRACH placed onthe terminal devices 508B, 508C by the PRACH access denial messages604A, 604B discussed above to be lifted. This is so that any one of theterminal devices in the group which subsequently generates new data foruplink is able to initiate a random access procedure to requestresources to transmit the new data to the base station 502. In thisrespect, whichever of the terminal devices in a group becomes the firstterminal device to initiate a new random access procedure may in effectbecome the new delegate terminal device. Processing may then continuefollowing the principles described above with reference to FIG. 6(taking account of a potential change in which of the terminal devicesis the delegate terminal device).

If a terminal device should fail to use the allocated resources at all,perhaps because it has lost power or is otherwise not receiving downlinksignalling or transmitting uplink signalling, then the base station willreceive no uplink data transmission and no rejection or insufficiencyindication. In some implementations this might cause the base station toassume a failure to receive correctly the transmissions the terminaldevice is expected to have made, and therefore to begin the use of HARQprocedures by sending a negative acknowledgement to the terminal device.Typically, this would repeat a number of times according to the basestation's configuration. Eventually, the limit of attempts to receivethe transmission from the terminal would be reached, when the basestation might then recognize the terminal device is not active, andpossibly remove the terminal device from the group to which it isassigned.

Expiration of the PRACH access denial applied for non-delegate terminaldevices may occur in a number of ways in different embodiments. Forexample, each terminal device may be configured to treat the PRACHaccess denial as being lifted/expired in respect of its owntransmissions after it has received its uplink grant 608B, 608C providedin response to another terminal device requesting resources. In otherexamples, the terminal devices may be configured to treat the PRACHaccess denial as having expired after a pre-determined period of time.In still other examples, terminal devices may be configured to treat thePRACH access denial as remaining in force until specific signalling isreceived from the base station to indicate the PRACH access denial islifted. A message indicating the PRACH access denial is lifted may, forexample, be sent from a base station to terminal devices in a mannercorresponding to that in which the PRACH access denial message is sent.

It will be appreciated that the processing represented in FIG. 6 may bemodified in accordance with other embodiments of the invention. Forexample, in some cases the PRACH access denial messages 604B, 604C maybe sent at a different time. For example, it may be consideredappropriate in some implementations to send the PRACH access denialmessages earlier to further reduce the likelihood of another terminaldevice independently initiating a RA procedure because it has data toupload before being instructed not to. For example, PRACH access denialmessages could be sent by the base station to non-delegate terminaldevices as soon as an RA preamble is received from another terminaldevice (which hence becomes the delegate terminal device) in a groupwith which the remaining non-delegate terminal devices are associated.In the event a terminal device independently initiates a RA procedurewhen another terminal device in its group has already initiated such aprocedure, but before the base station has transmitted any associatedPRACH access denial messaging, the base station may be configured tosimply ignore the later-received PRACH transmissions. The terminaldevice whose PRACH transmissions are ignored in accordance with someembodiment of the invention may eventually receive a PRACH access denialmessage and hence be configured to cease any PRACH (re)transmissions itmight otherwise have made.

In accordance with some embodiments of the invention the base station502 may transmit PRACH access denial messages 604B, 604C to all terminaldevices in a group associated with a delegate terminal device whichinitiates a random access procedure. However, in some other embodimentsthe base station may send PRACH access denial messages 604B, 604C toonly a subset of the terminal devices in a group associated with adelegate terminal device which initiates a random access procedure.Terminal devices which are not sent a PRACH access denial message aretherefore still permitted to access PRACH in the usual way, but willnonetheless also be pre-emptively allocated resources in accordance withthe principles described above. Terminal devices in a group which arenot forbidden to access PRACH (i.e. not sent a PRACH access denialmessage) could include terminal devices which are classified as having arelatively high priority among the terminal devices in the group, forexample. In other cases, however, it may be more appropriate for suchterminals devices to be removed from the relevant grouping instead.

In accordance with some embodiments a terminal device may have multipledifferent traffic profiles associated with multiple different types ofdata for uplink communication. That is to say, in accordance with someembodiments a terminal device may be associated with more than onetraffic class simultaneously and may therefore be considered as being inin more than one group of terminal devices with related trafficprofiles. In such cases any signalling to a terminal device denying itaccess to PRACH may also include an assignment of that denial to aparticular traffic class (or classes). Accordingly, it may be that aterminal device is only barred from making PRACH transmissions withrespect to those traffic classes, at least when they would normallyresult in PRACH access. Traffic classes associated with particularlyhigh priority QCIs might be given such exceptions, for example, so thata terminal device can send a BSR overriding that provided by a terminaldevice which has acted as a group's delegate according to the principlesdescribed above with reference to FIG. 6. This could therefore allow aterminal device to provide its own BSR with respect to a particulartraffic class faster than would be possible by waiting for the chance tosend a rejection or insufficiency indicator as described above.

In the above-described embodiments a base station configured to allocateresources to what might be termed a non-delegate terminal device basedon a request for resources received from what might be termed a delegateterminal device is also configured to transmit PRACH access denialsignalling to the non-delegate terminal device(s) to indicate thenon-delegate terminal device(s) should not attempt to access PRACH, atleast temporarily. In the above-described embodiments a terminal devicemay attempt to access PRACH in the usual manner if it has not previouslyreceived RACH access denial signalling (and hence may in fact become adelegate terminal device). However, in accordance with some otherembodiments, terminal devices may be configured to determine themselvesthat they should not attempt to access PRACH resources (i.e. they shouldnot initiate a random access procedure), at least for a period of time,in the expectation they will be allocated radio resources by the basestation based on a request for radio resources made by another terminaldevice. This may in some respects be referred to as PRACH self-denial onthe part of the terminal device.

For example, a terminal device may come to a state in accordance withits normal operation whereby it is ready to initiate a random accessprocedure. However, rather than doing so, the terminal device may decideinstead to delay accessing PRACH in the expectation that anotherterminal device having a similar traffic profile, and hence classifiedas being grouped with the terminal device at the base station, willshortly initiate a random access procedure of its own. In effect,certain terminal devices may be configured to wait for another terminaldevice to become a delegate terminal device to allow the terminal deviceto receive radio resources without having to access PRACH (e.g. inaccordance with the principles set out above with reference to FIG. 6).This approach can be advantageous for the self-denying terminal deviceas it will save battery power, for example.

To avoid a self-denying terminal device waiting for an undue length oftime for another terminal device to initiate a random access procedure,it may be configured to initiate its own random access procedure ifanother terminal device does not do so within a given time window. Thetime window adopted for different types of data may be different. Forexample, data which is considered to have higher priority may beassociated with a smaller time window, perhaps even as low as zero timewindow, corresponding to the self-denying terminal device not denyingitself access to PRACH for that particular class of data. In any case,the length and ability to use the self-denial (speculative) PRACHtransmission delay window(s) by a terminal device can, for example, bean implementation choice of the terminal device manufacturer and/orconfigured by the base station via RRC signalling for all or someterminal devices.

As already mentioned, the above-described embodiments primarily focus onimplementations in which a base station is configured to transmit PRACHaccess denial signalling to non-delegate terminal devices to indicatethey should not attempt to access PRACH. Thus, in accordance with theseexamples all terminal devices may assume they may access PRACH unlessthey are instructed otherwise through PRACH access denial signalling.However, in accordance with other embodiments, terminal devices may beconfigured to assume they should not attempt to access PRACH unless theyare instructed that they may do. Thus, instead of simply allowingwhichever terminal device first initiates each random access procedureto become the delegate terminal device, in some embodiments one or moreterminal devices may be pre-defined as a delegate terminal device andinstructed that they may access PRACH whilst other terminal devices maybe configured to not access PRACH and to rely solely on pre-emptiveresource allocations of the kind described above. A base station mayselect one or more terminal devices to be allowed PRACH access (andhence act as a delegate terminal device) for the terminal devices of aparticular group of terminal devices with related traffic profilesrandomly or systematically. For example, the selection of one or morepotential delegate terminal devices from within a group of terminaldevices may be made on the basis of radio channel quality informationassociated with the respective terminal devices. For example, terminaldevices with higher quality radio channel communications with the basestation, for example because they are nearer to the base station, may beselected as potential delegate terminal devices to help with theprobability that PRACH transmissions arrive at the base station quickly,allowing any subsequent denial signalling to be sent as early aspossible and for the received signal quality on the preamble to be asgood as possible. Thus the selection may be based on calculationsperformed but at the base station taking account of parameters such asTiming Advance (TA) associated with the terminal devices in the group.Other metrics which might be used include the (filtered, layer 3) radioresource management (RRM) measurements based on RSRP (reference signalreceived power)/RSRQ (reference signal received quality), or SRS(sounding reference signal) measurements at the base station.

In accordance with some other example embodiments, terminal devicesoperable in accordance with the principles described above might beprovided with a configuration relevant to MBSFN (Multicast BroadcastSingle Frequency Network) operation, wherein at the physical layercertain subframes within certain radio frames may be defined as for useonly for multicast or broadcast data. To each group of terminal devicescan be associated an MBMS (Multimedia Broadcast Multicast Service)service. Then, PRACH denial signalling might be multicast to a group ofterminal devices using MBMS, thereby helping reduce the resources usedfor this signalling as compared to individual signalling to each of thepotentially many access-denied (“barred”) terminal devices. Onlyterminal devices configured with the MBMS service for which the PRACHdenial is sent might then act in response to it (by suppressing RACHaccesses). In accordance with this approach the base station need notknow how many terminal devices are presently in the group, allowing themto be switched on and off without informing the network or requiring avariable amount of resource to transmit PRACH denial signalling.

In example implementations in accordance with embodiments of theinvention, there are various ways in which terminal devices can beconfigured to only access PRACH if they are one of the pre-definedallowable dedicated terminal devices are selected by the base station.For example, in a system where terminal devices are configured togenerally assume they are allowed to access PRACH, the base station maybe configured to send PRACH denial signalling to all terminal devices,apart from the selected potential delegate terminal device(s), even ifthere is no currently on-going random access procedure from a terminaldevice in the associated group of terminal devices. Alternatively, in asystem where terminal devices are configured to generally assume theyare not allowed to access PRACH, the base station may be configured tosend signalling to the selected potential delegate terminal device(s) toindicate they are allowed to access PRACH.

In accordance with further embodiments of the invention, a wirelesstelecommunications system may operate in a device-to-device (D2D) modewhereby the terminal devices communicate directly with one another usingthe same cellular technology (or possibly a different wireless bearer)as they use to communicate with the infrastructure network/base stationprovided by the operator. Such D2D architectures can have variousadvantages known in the art, including but not limited to, network-sidepower reduction, RAN traffic load reduction, and terminal-side powerreduction. Thus, terminal devices operating in a D2D mode and requiringan allocation of uplink resource can send a BSR (or actual uplink datadepending on the specific D2D implementation) to one designated terminaldevice which collates them to generate a total group BSR and providesthis to the network via RACH in accordance with broadly conventionaltechniques. Having sent their own BSR to the designated terminal device,the other terminal devices may be configured to regard themselves asbeing prohibited from accessing RACH/PRACH in their own right. Inaccordance with principle similar to those described above with regardsto FIG. 6, the base station scheduler may then schedule the entire groupof terminal devices and provide the relevant uplink grants on PDCCH.These may either be transmitted to each terminal device individually orto the delegate terminal device for onward D2D transmission to theindividual terminal devices according to the specific D2D implementationat hand. The C-RNTIs of the terminal device in the D2D set are assumedto be known to the base station to support this downlink signalling ofuplink grants.

Thus, there has been described various ways in which a base station mayconveniently allocate resources to one terminal device based on arequest received from another terminal device where the two terminaldevices are classified as being in a group on the basis of theirexpected traffic profiles, for example, taking account of predictedtimings and amounts of data for uplink from the respective terminaldevices. In doing this, it can be possible to schedule uplink resourcesfor a plurality of terminal devices with less signalling associated withrandom access procedures than would otherwise be the case. Theassociations among terminal devices (i.e. the groupings) may bemaintained (and potentially modified) by the base station, for examplebased on inherent characteristics of the devices, such as theiroperating functions, or based empirically on previous data transferbehaviour associated with the respective terminal devices. In general,the terminal devices do not need to be aware of what other terminaldevices are in their group, and as such the associations betweenterminal devices may be maintained internally at the base stationwithout communication to the terminal devices.

Thus, embodiments of the invention can help reduce the potentiallyimpact of PRACH to PUSCH interference, especially in the context of anarrowband LTE-type carrier, such has been proposed for so-calledvirtual carriers, and also in the context of MTC terminal devices whichmay be deployed more densely than other types of terminal device, andfurthermore may be more predictable and similar in their trafficprofiles. By reducing, potentially to one, the number of terminaldevices in a traffic group that have permission to access PRACH for agiven time, the potential interference to PUSCH can be correspondinglyreduced.

Furthermore, in accordance with some embodiments of the invention theremay be an overall reduction in transmissions and retransmissions fromterminal devices as compared to conventional systems becausetransmissions on PRACH are carried out only by the delegated terminaldevice(s) among a group. This can reduce power consumption for terminaldevices, thus increasing their battery life. This can be particularlyrelevant for MTC devices.

Furthermore, in accordance with some embodiments contention on RACHcould be reduced by virtue of the delegation of the random accessprocedure to a restricted number of terminal devices, for example to thefirst terminal device to transmit PRACH among a group rather thancontinuing to allow them all to potentially contend. This could furtherreduce terminal device power consumption for most terminal devices in agroup, and also help reduce the latency of RACH.

Furthermore, in accordance with some embodiments there may be reduceduplink intercell interference because of the potential reduction in theamount of uplink PRACH transmissions.

Some significant differences associated with certain embodiments of theinvention as compared to conventional approaches include following:

The concept of one terminal device acting as a random access delegatefor a group of terminal devices is not known in conventional systems.For example, in a conventional LTE-type network each terminal device isresponsible for its own scheduling requests, BSRs, and RACH procedures.

Allowing a terminal device to remain connected to a cell but to beexplicitly denied access to PRACH/RACH by downlink signalling is notavailable in conventional wireless telecommunications systems.

Conventional wireless telecommunications system do not allow for a basestation to allocate uplink resources to a terminal device which has notrequested them.

The concept of providing for a differential BSR to allow a terminaldevice to communicate a desired adjustment to an amount of resource ithas been allocated is not available in conventional wirelesstelecommunications networks.

Conventional wireless telecommunications networks do not allow for aterminal device to speculatively delay its own PRACH transmission in thehope that another terminal device may act as a group delegate is notpreviously disclosed (linked with the first bullet point). Thenetwork-based configuration version of this embodiment represents adeparture from current LTE specifications where no such capabilityexists.

It will be appreciated that various modifications can be made to theembodiments described above without departing from the scope of thepresent invention as defined in the appended claims. In particularalthough embodiments of the invention have been described with referenceto a LTE mobile radio network, it will be appreciated that the presentinvention can be applied to other forms of network such as GSM, 3G/UMTS,CDMA2000, etc. The term user equipment (UE) as used herein can bereplaced with other terms user equipment (UE), mobile communicationsdevice, terminal device etc. Furthermore, although the term base stationhas been used interchangeably with eNodeB it should be understood thatthere is no difference in functionality between these network entities.

Thus, there has been described a method of allocating radio resourcesfor uplink transmissions in a wireless telecommunications system, themethod comprising: a first terminal device communicating a request foran allocation of radio resources to a base station; the base stationdetermining there is an association between the first terminal deviceand a second terminal device based on their having similar predictedtraffic profiles for uplink data; and the base station establishing aradio resource allocation for the second terminal device based on theresources requested by the first terminal device, and consequentlytransmitting radio resource allocation messages to allocate radioresources to the first and second terminal devices for respective uplinktransmissions based on the request for an allocation of radio resourcesreceived from the first terminal device.

Thus in some respects certain embodiments of the invention provide forschemes to help allow one UE to act as a delegate for a group of UEswith respect to accessing RACH and making transmissions on PRACH. Thegroup of UEs may have something common about their expected trafficprofiles, for example QCIs, so that when a buffer status report (BSR) istriggered at one UE, the eNB can assume that a similar BSR is likely tobe about to be triggered at the other UEs in the group. Therefore, theeNB can conduct the uplink (UL) scheduling process with this assumptionand signal to the other UEs in the traffic profile group a denial ofpermission to transmit PRACH for the time being. After providing adetermined UL schedule to all UEs in the group via usual PDCCH DCImessages, some embodiments allow UEs to reject the scheduled grants orindicate that they are insufficient. Embodiments of the invention maytherefore help reduce interference between PRACH and PUSCH/PUCCH by ineffect reducing the number of UEs likely to be transmitting PRACH at anyone time simultaneously and in a similar manner could help reduce theload on RACH and the probability of RACH contention.

Further particular and preferred aspects of the present invention areset out in the accompanying independent and dependent claims. It will beappreciated that features of the dependent claims may be combined withfeatures of the independent claims in combinations other than thoseexplicitly set out in the claims.

REFERENCES

-   [1] ETSI TS 122 368 V10.530 (2011 July)/3GPP TS 22.368 version    10.5.0 Release 10-   [2] Holma H. and Toskala A, “LTE for UMTS OFDMA and SC-FDMA based    radio access”, John Wiley and Sons, 2009-   [3] ETSI TS 136 321 V10.6.0 (2012 October)/3GPP TS 36.321 version    10.6.0 Release 10-   [4] ETSI TS 136 300 V10.8.0 (2012 July)/3GPP TS 36.300 version    10.8.0 Release 10-   [5] UK patent application GB 1101970.0-   [6] UK patent application GB 1101981.7-   [7] UK patent application GB 1101966.8-   [8] UK patent application GB 1101983.3-   [9] UK patent application GB 1101853.8-   [10] UK patent application GB 1101982.5-   [11] UK patent application GB 1101980.9-   [12] UK patent application GB 1101972.6-   [13] UK patent application GB 1121767.6-   [14] UK patent application GB 1121766.8-   [15] ETSI TS 123 401 V10.8.0 (2012 July)/3GPP TS 23.401 version    10.8.0 Release 10-   [16] ETSI TS 123 203 V10.7.0 (2012 July)/3GPP TS 23.203 version    10.7.0 Release 10

1. A method of operating a terminal device for receiving an allocationof radio resources for transmission of uplink data to a base station ina wireless telecommunications system, the method comprising: determiningthat the terminal device has uplink data waiting for transmission to thebase station; determining that the terminal device should not transmit arequest for an allocation of radio resources for transmission of theuplink data to the base station, and waiting to receive a radio resourceallocation message from the base station to allocate radio resources tobe used for transmissions associated with the uplink data waiting fortransmission to the base station.
 2. A method according to claim 1,wherein determining that the terminal device should not transmit arequest for an allocation of radio resources comprises determining thatthe terminal device should not initiate a random access procedure of thewireless telecommunications system.
 3. A method according to claim 2,wherein determining that the terminal device should not initiate arandom access procedure of the wireless telecommunications systemcomprises determining that the terminal device should not maketransmissions on a physical random access channel of the wirelesstelecommunications system.
 4. A method according to claim 1, whereindetermining that the terminal device should not transmit a request foran allocation of radio resources is based on the terminal devicereceiving an indication that the terminal device should not transmit arequest for an allocation of radio resources.
 5. A method according toclaim 4, wherein the indication comprises an indication that anotherterminal device in the wireless telecommunications system has made arequest for an allocation of radio resources.
 6. A method according toclaim 1, wherein determining that the terminal device should nottransmit a request for an allocation of radio resources is based on theterminal device having received an access request denial message fromthe base station.
 7. A method according to claim 1, further comprisingsubsequently receiving the radio resource allocation message from thebase station.
 8. A method according to claim 7, further comprisingtransmitting the uplink data waiting for transmission to the basestation using radio resources derived from information in the radioresource allocation message received from the base station.
 9. A methodaccording to claim 8, further comprising determining at a later timeafter having transmitted the uplink data to the base station that theterminal device has further uplink data waiting for transmission to thebase station, and, in response thereto, determining that the terminaldevice should transmit a request for an allocation of radio resources onwhich to transmit the uplink data to the base station, and transmittingsuch a request.
 10. A method according to claim 9, wherein determiningthat the terminal device should transmit a request for an allocation ofradio resources in response to determining that the terminal device hasfurther uplink data waiting for transmission to the base station isbased on the terminal device having received an access request allowmessage from the base station to indicate the terminal device is allowedto make a request for an allocation of radio resources.
 11. A methodaccording to claim 7, further comprising determining that the allocationof radio resources is not sufficient for the uplink data waiting fortransmission to the base station and transmitting to the base station anindication of a request for a further allocation of radio resources inresponse thereto.
 12. A method according to claim 11, wherein theindication of a request for a further allocation of radio resources istransmitted to the base station using the allocated radio resources. 13.A method according to claim 1, further comprising transmitting a requestfor an allocation of radio resources on which to transmit the uplinkdata to the base station after waiting to receive a radio resourceallocation message from the base station for a period of time without aradio resource allocation message being received from the base station.14. A method according to claim 1, wherein the terminal device is amachine type communication, MTC, terminal device.
 15. A method accordingto claim 1, wherein the wireless telecommunications system is associatedwith a radio interface spanning a system frequency bandwidth forsupporting radio communications with a first type of terminal device andcomprising a restricted frequency bandwidth for supporting radiocommunications with a second type of terminal device, wherein therestricted frequency bandwidth is narrower than and within the systemfrequency bandwidth, and wherein the terminal device is a terminaldevice of the second type.
 16. A terminal device arranged to receive anallocation of radio resources for transmission of uplink data to a basestation in a wireless telecommunications system, wherein the terminaldevice is configured to: determine that the terminal device has uplinkdata waiting for transmission to the base station; determine that theterminal device should not transmit a request for an allocation of radioresources for transmission of the uplink data to the base station, andwait to receive a radio resource allocation message from the basestation to allocate radio resources to be used for transmissionsassociated with the uplink data waiting for transmission to the basestation.
 17. A terminal device according to claim 16, wherein theterminal device is configured such that determining that the terminaldevice should not transmit a request for an allocation of radioresources comprises determining that the terminal device should notinitiate a random access procedure of the wireless telecommunicationssystem.
 18. A terminal device according to claim 17, wherein theterminal device is configured such that determining that the terminaldevice should not initiate a random access procedure of the wirelesstelecommunications system comprises determining that the terminal deviceshould not make transmissions on a physical random access channel of thewireless telecommunications system.
 19. A terminal device according toclaim 16, wherein the terminal device is configured such thatdetermining that the terminal device should not transmit a request foran allocation of radio resources is based on the terminal devicereceiving an indication that the terminal device should not transmit arequest for an allocation of radio resources.
 20. A terminal deviceaccording to claim 19, wherein the indication comprises an indicationthat another terminal device in the wireless telecommunications systemhas made a request for an allocation of radio resources.
 21. A terminaldevice according to claim 16, wherein the terminal device is configuredsuch that determining that the terminal device should not transmit arequest for an allocation of radio resources is based on the terminaldevice having received an access request denial message from the basestation.
 22. A terminal device according to claim 16, wherein theterminal device is further configured to subsequently receive the radioresource allocation message from the base station.
 23. A terminal deviceaccording to claim 22, wherein the terminal device is further configuredto transmit the uplink data waiting for transmission to the base stationusing radio resources derived from information in the radio resourceallocation message received from the base station.
 24. A terminal deviceaccording to claim 23, wherein the terminal device is further configuredto determine at a later time after having transmitted the uplink data tothe base station that the terminal device has further uplink datawaiting for transmission to the base station, and, in response thereto,to determine that the terminal device should transmit a request for anallocation of radio resources on which to transmit the uplink data tothe base station, and to transmit such a request.
 25. A terminal deviceaccording to claim 24, wherein the terminal device is configured suchthat determining that the terminal device should transmit a request foran allocation of radio resources in response to determining that theterminal device has further uplink data waiting for transmission to thebase station is based on the terminal device having received an accessrequest allow message from the base station to indicate the terminaldevice is allowed to make a request for an allocation of radioresources.
 26. A terminal device according to claim 22, wherein theterminal device is further configured to determine that the allocationof radio resources is not sufficient for the uplink data waiting fortransmission to the base station and to transmit to the base station anindication of a request for a further allocation of radio resources inresponse thereto.
 27. A terminal device according to claim 26, whereinthe terminal device is configured such that the indication of a requestfor a further allocation of radio resources is transmitted to the basestation using the allocated radio resources.
 28. A terminal deviceaccording to claim 16, wherein the terminal device is further configuredto transmit a request for an allocation of radio resources on which totransmit the uplink data to the base station after waiting to receive aradio resource allocation message from the base station for a period oftime without a radio resource allocation message being received from thebase station. 29-31. (canceled)